The present disclosure relates to a liquid crystal display (hereinafter referred to as LCD) provided with a light source section having a plurality of emission subsections.
In recent years, as a thin-screen television and a display of a portable terminal device, an active matrix type of LCD in which a thin film transistor (TFT) is provided for each pixel has been often used. In such a LCD, each pixel is driven by line-sequentially writing an image signal in an auxiliary capacitive element and a liquid crystal element of each pixel from an upper part to a lower part of a screen.
As a backlight used in the LCD, a backlight using a cold cathode fluorescent lamp (CCFL) as a light source is mainstream, but in recent years, a backlight using a light emitting diode (LED) has also appeared.
For the LCD that employs such an LED as a backlight, there has been proposed, in related art, a technique in which a light source section is divided into a plurality of emission subsections, and which performs emission operation independently on this emission subsection basis (for example, see Japanese Unexamined Patent Application Publication No. 2001-142409). At the time of such sub-sectional emission operation, each of an emission pattern signal indicating an emission pattern for each emission subsections in the backlight and a partitioning-drive image signal is generated based on an input image signal.
Meanwhile, in order to achieve low power consumption at the time of image display in the LCD, a technique in which each pixel in a LCD panel includes sub-pixels of four colors has been proposed. These sub-pixels of four colors are, specifically, a red (R)-sub-pixels, a green (G)-sub-pixel, a blue (B)-sub-pixel, and a Z-sub-pixel, Z-sub-pixel exhibiting a color of Z (for example, white (W), yellow (Y), or the like) with luminance higher than that of the R-, G-, and B-sub-pixels. When image display is performed by using image signals for such sub-pixels of four colors, as compared to a case in which image display is performed by supplying an image signal for three colors to each pixel having a sub-pixel structure of three colors of R, G, and B as in the past, luminance efficiency may be improved. In other words, display luminance may be maintained while the signal level is reduced and thus, low power consumption may be achieved as compared to a LCD having the sub-pixel structure of the three colors in the past.
In addition, Japanese Patent No. 4354491 proposes the combination of the above-described two techniques, namely, a technique in which sub-sectional emission operation is performed in a LCD having a sub-pixel structure of four colors of R, G, B, and W.